The Fugitive Slave Act or Fugitive Slave Law was a law passed by the 31st United States Congress on September 18, 1850, as part of the Compromise of 1850 between Southern interests in slavery and Northern Free-Soilers.

an Act of the United States Congress to give effect to the Fugitive Slave Clause of the U.S. Constitution (Article IV, Section 2, Clause 3), which was later superseded by the Thirteenth Amendment, and to also give effect to the Extradition Clause (Article 4, Section 2, Clause 2).